Shedding mechanism



Aug.-22, 1944. J. M. TUTEN I SHEDDING MECHANISM Filed Jan 20, 1944 2 Sheets-Sheet 1 INVENTOR \JA/VES M TUTEN Y F- N R O T T A Aug. 22, 1944. J. M. TUTEN S'ILIEDDING MECHANISM Filed Jan. 20, 1944 Z'Sheets-Sheet 2 INVENTOR. JAMES M TUTE/V TATTORNEY Patented Aug. 22, 1944 S'E'TES SHEDDING MECHANISM Application January 20, 1944, Serial No. 518,987

rm OFFICE The present invention relates generally to shedding mechanisms for looms and, as illustrated herein, relates more particularly to the cam type of such mechanisms.

Looms of the type to which the present invention pertains are provided with a plurality of harness frames which are reciprocated by harness treadles which in turn are reciprocated about a fixed axis by suitable cams. The throw of the cams and the length of the treadle are properly proportioned to produce a movement of the harness frames which will provide the desired opening of the warp to permit passage of the shuttle. This opening is necessarily kept as small as possible and hence must be varied in accordance with the size of the shuttle and with other weaving conditions. For this reason a very large number of sizes of harness cams is required, both for equipping new looms and for replacement purposes in adapting existing looms to different weaving conditions.

To avoid this undesirable condition, it has been proposed to make the shedding mechanism adjustable to provide a plurality of warp openings of different widths from a single harness cam. The construction disclosed and claimed in the patent to Brown No. 2,042,422, granted May 26, 1936, has successfully solved this problem and has gone into extensive commercial use. In this construction, an elongated gear member extends transversely of the treadles and constitutes the fulcrum therefor. The treadles at their rear ends are provided with gear teeth which mesh with the teeth on the gear member which is adjustable longitudinally of said treadles. This adjustment of the gear member varies the fulcrum point and thereby controls the warp opening.

The above construction effectively provides for the desired range of adjustment but under some conditions where it is either desirable or necessary to control the extent of the warp opening between very close limits, lost motion between the parts may prevent such very close control. This lost motion results in an appreciable movement of the elongated gear member and hence results in considerable movement of the fulcrum point of the treadles with resultant variation in the warp opening.

One object of the present invention is to provide an improved shedding mechanism whereby the above mentioned undesired variation is eliminated. To this end, means are provided'for looking the elongated gear member in adjusted position. As illustrated, set screws are provided for looking the elongated gear member in adjusted position thus eliminating any rocking thereof which might result-in an appreciable change of warp opening.

With the above and other objects and features in view, the invention will now be described with particular reference to the accompanying drawings which illustrate a preferred embodiment of the invention and in which- Fig. 1 is a view partlyin section and partly in elevation of a loom showing the shedding mechanism to which the present invention has been applied;

Fig. 2 is a plan view of the shedding mechanism;

Fig. 3 is a sectional view taken along the line IIIIII of Fig. 2;

Fig. 4 is a perspective view of the end of the present device; and

Fig, 5 is a sectional view taken along line V-V of Fig. 4. v

The m shown in the drawings is of conventional construction and hence is not completely shown since it is not necessary to a complete understanding of the present invention. The conventional parts of the loom include the right hand loom side H] which is connected by a plurality of cross girts l2 to left hand loom side (not shown). This loom is alsoprovided with a crank shaft M, a cam shaft l6, and an auxiliary shaft l8 which carries a, plurality of harness cams 20.

The illustrated loom is provided with harness frames 22 which extend widthwise of the loom and are substantially vertical and are reciprocated vertically by the harness cams 20 and treadles 24 which are positioned below the harness frames. The shedding mechanism shown is further conventional in that the harness treadles 24 are parallel and are positioned sideby side and extend rearwardly from the harness frames 22. The forward end of each treadle is connected to a harness frame by any usual means such as a strap 26.

The rotating harness cams 20 are positioned above the treadles 24 and intermediate the ends thereof. Each harness cam serves to depress its respective treadle through engagement with a roller 28 thereon. The harness treadles are fulcrumed at their rear ends and depression of a treadle results in a connected harness frame being depressed a distance which corresponds to the throw of the forward end of the treadle. The harness frame is raised after being depressed by any well known means, any of the usual spring mechanisms being well adapted for this purpose.

The fulcrum for the treadles 24 comprises an elongated gear member 30 which has axially extending teeth 32 meshing with teeth 34 on the treadles 24. The member 30 is sufiiciently long to engage and support all of the harness treadles 24. The gear member 39 is normally fixed and the treadles rock thereon. The gear member is shifted rearwardly or forwardly to vary the throw of the treadles, thereby varying the size of warp opening obtainable from one set of harness cams.

The gear member 30 is adjustably mounted in brackets 36, 38 which in turn are bolted to brack-- ets 40 and 42, respectively. Bolts 44, 4B secure these brackets 40 and 42 to middle girts 48, 50. The brackets 36, 38 except for the fact that they are right and left hand brackets respectively are substantially identical and hence it will be necessary only to describe one of the brackets in detail. The bracket 36 is provided with an inwardly extending horizontal shelf 52 having depending rack teeth 54 formed on the lower surface thereof and meshing with the teeth 32 formed on the gear member 30.

The member 30 is provided with a trunnion 56 at each end which fits into a substantially horizontal slot 51 formed in each bracket. Thus, the slot 51 is substantially parallel to the rack 52 and when the elongated gear 30 is rotated, the trunnion 56 will slide forwardly or rearwardly in the slot 51 to bring different teeth 54 and 32 into mesh. If the gear member 311 is rotated to move forwardly, for example, the teeth 32 of the member 30 will then mesh with teeth 34 which are nearer the forward end of the levers 24. Likewise, if the gear member 30 is rotated to move rearwardly, the gear teeth 32 will then mesh with the teeth 34 which are nearer the rear ends of the levers 24. When the member 30 is moved forwardly the ratio between the lever arms isincreased and thus permits a. wide shed opening of the harness. When the member 30 is moved rearwardly, the ratio between the lever arms is decreased and hence a smaller shed opening is formed. The difference between the smallest and the largest shed opening which it isposs ble to obtain with one cam is suificiently great to take care of most conditions. described is substant ally the same as disclosed in the aforementioned Letters Patent.

The construction so far With the present construction, the smallest changes may be made and hence any desired warp opening is possible within the limits of that particular combination of parts. In order to take advantage of this fine adjustment, it is desirable to provide means for locking the gear member 39 in adjusted position. To this end, the right hand bracket 36 is provided with two stop screws 58. 58 which are threaded into and through substantially vertical openings formed in the shelf 52. These open ngs are so located that they extend through spaced teeth 54 on the under side of the shelf 52. Thus, the stop screws 58 will enter between the teeth 32 on the elongated gear member and when the screws are manually tightened down between the teeth 32, the gear member 36 will be rigidly held in adjusted position at that end. The screws 58 are locked in adjusted position by lock nuts 60.

The bracket 38 is provided with a shelf 62 similar to the shelf 52 on the bracket 36. This bracket 62 is provided with depending rack teeth (not shown) which mesh with the teeth 32 on the elongated gear member 30. The shelf 62 is provided with a single locking screw 64 which is substantially the same as the locking screw 58 and which is locked in adjusted position by a lock nut 66. Thus, both ends of the elongated gear member 33 are rigidly secured in position.

With the above construction, it is evident that very fine adjustments may be made if so desired and the elongated gear member 30 locked in said position. Thus, the warp opening can be accurately controlled and wherein the warp opening may be varied or adjusted without the necessity of changing harness cams.

Having thus described a preferred embodiment of the present invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. In a loom, a harness frame, a harness treadle connected with said frame for operating the latter, a cam for operating the treadle, a gear member forming an adjustable fulcrum for the treadle and having gear teeth meshing with rack teeth on said treadle, means for adjustably supporting said gear member, and manually operated locking means on said supporting .means engaging teeth on said gear member and locking said gear member in adjusted position.

2. In a loom, a harness frame, a harness treadle connected with said frame for operating the latter, a cam for operating the treadle, a gear member on which the treadle is fulcrumed, said gear member having gear teeth extending transversely of said treadle and meshing with rack teeth formed thereon, means for support ng the gear member for rollin movement longitudinally of the treadle to adjust the fulcrum point of the treadle, and manually operated stop means extending through said supporting means and engaging spaced gear teeth on said gear member for locking said gear member in adjusted position.

3. In a loom, a harness frame, a harness treadle connected with said frame for operat ng the latter, a cam for operating the treadle, a gear member on which the treadle is fulcrumed, said gear member having gear teeth extending transversely of saidtreadle and meshing with rack teeth formed on said treadle, means for supporting said gear member for rolling movement longitudinally of the treadle to adjust the fulcrum point of the treadle, means fixed to said supporting means and having rack teeth meshing with said gear teeth on said gear member and stop screws extending through said last mentioned means and engaging said gear teeth to lock said gear member in adjusted position.

4. In a loom, a harness frame, a harness treadle connectedwith said frame for operating the latter, a cam for operating the treadle, a gear member on which the treadle is fulcrumed, said gear member having gear teeth extending transversely of said treadle and meshing with rack teeth formed on said treadle, means for supporting said gear member for rolling movement longitudinally of the treadle to adjust the fulcrum point of the treadle, a shelf on said supporting means having depending rack teeth meshing with the gear teeth on said gear member, and a pair of stop screws threaded through said shelf and engaging said gear teeth to lock said gear member in adjusted position.

5. In a loom, a harness frame, a harness treadle connected with said frame for operating the latter, a cam for operating the treadle, a gear member on which the treadle is fulcrumed, said 'gear member having gear teeth extending transverse- 1y of said treadle and meshing with rack teeth formed on said treadle, means for supporting said gear member for rolling movement longitudinally of the treadle to adjust the fulcrum point of the treadle, said supporting means being located at each end of said gear member, a shelf on said supporting means adjacent to each end of said gear member and having rack teeth meshing with said gear teeth on said gear member, stop screws extending through one of said shelves and engaging spaced teeth on one end of said gear member, andstop means on the other shelf engaging'said gear teeth at the other end of said gear member, said stop screws and said stop means being effective to lock said gear member in adjusted position.

6. In a loom, a harness frame, a harness treadle connected with said frame for operating the latter, a cam for operating the treadle, a gear memher on which the treadle is fulcrumed, said gear member having gear teeth extending transversely of said treadle and meshing with rack teeth formed on said treadle, means for supporting said gear member for rolling movement longitudinally of the treadle to adjust the fulcrum point of the treadle, said supporting means being located at each end of said gear member, a shelf on said supporting means adjacent to each end of said gear JAMES M. TUTEN. 

